QuickSIN ™

Speech-in-Noise TestVersion 1.3

E T Y M O T I C R E S E A R C H I N C .

TABLE OF CONTENTS

Quick Start ..........................................................................................................3Purpose of the QuickSIN ..................................................................................4QuickSIN methodology ......................................................................................4What’s on this CD? ............................................................................................5How to use this CD ............................................................................................6

Set-upCalibrationPresentation LevelTest Instructions

Practice lists ......................................................................................................7What is SNR loss? ..............................................................................................8Scoring ............................................................................................................8-9Where does the number 25.5 come from? ......................................................9The formula for SNR loss ..................................................................................9Guilt-Free QuickSIN test for ski-slope loss ....................................................10

High-frequency Lists Low-pass Filtered Lists

Separated speech and noise channels............................................................11Directional comparisons ............................................................................11-13Test development ........................................................................................14-18

Original SIN TestSIN Test FormatOrigin of SIN Test MaterialsProblems with the SIN TestBackground NoiseQuickSIN Search for Sentence Equivalence

Alpha VersionsBeta Version

Reliability (Statistics made useful) ............................................................19-20Score sheets................................................................................................21-23

Lists 1-6 Lists 7-12 Lists 13-18 (pairs)

Appendices ..................................................................................................24-25References ........................................................................................................26

2

QUICK START (for full instructions, see page 6)

• Connect a CD player to the speech circuit of a standard audiometer.

• Using the calibration tone on Track 1, adjust both channels of the audiometerto read 0 VU. NOTE: Except for tracks 24-35, the target speech andbackground talkers were recorded together on both channels.

• Present the test with earphones or in a sound field, with the attenuator dial setto 70 dB HL. For subjects with PTA hearing losses greater than 45 dB HL, setthe attenuator dial to a level that is “loud but OK.”

• Instruct the patient to repeat the sentences spoken by the target (female) talker.

• When testing in a sound field, have the patient hold the talkback microphoneclose enough so that responses are clearly audible to the tester.

• Score the five key words underlined in each sentence, giving one point foreach word repeated correctly.

• Add the number of words repeated correctly, totalled across all 6 sentences.Subtract the total correct from 25.5 to obtain SNR loss.

SNR Loss = 25.5 – Total Correct.

• To interpret the SNR loss score, see Table 1.

Table 1

SNR LOSS DEGREE OF SNR LOSS EXPECTED IMPROVEMENT WITH DIRECTIONAL MIC

0-3 dB Normal/near normal May hear better than normals hear in noise

3-7 dB Mild SNR loss May hear almost as well as normals hear in noise

7-15 dB Moderate SNR loss Directional microphones help. Consider array mic

>15 dB Severe SNR loss Maximum SNR improvement is needed. Consider FM system

3

PURPOSE OF THE QuickSIN

The primary complaint of hearing-impaired persons is difficulty hearing inbackground noise. The measurement of SNR loss (signal-to-noise ratio loss) isimportant because speech understanding in noise cannot be reliably predictedfrom the pure tone audiogram (Killion & Niquette, 2000).

The QuickSIN test was developed to:

• Provide a one-minute estimate of SNR loss

• Provide a quick way for clinicians to quantify a patient’s ability to hear in noise

• Determine if extended high frequency emphasis improves or degrades understanding of speech in noise

• Assist professionals in choosing appropriate amplification and other assistive technologies

• Demonstrate that hearing aids with directional microphones improve speech intelligibility in noise

• Provide a large number of equivalent test lists for use in clinical and research work

• Provide information useful in counseling patients regarding realisticexpectations

QuickSIN METHODOLOGY

A list of six sentences with five key words per sentence is presented in four-talkerbabble noise. The sentences are presented at pre-recorded signal-to-noise ratioswhich decrease in 5-dB steps from 25 (very easy) to 0 (extremely difficult). TheSNRs used are: 25, 20, 15,10, 5 and 0, encompassing normal to severely impairedperformance in noise.

4

WHAT’S ON THIS CD?

The QuickSIN CD contains lists of sentences in noise (4-talker babble) that can beused to determine SNR Loss (signal-to-noise ratio loss). Each list takes about oneminute to administer. There are eight blocks of recordings on this CD:

• 12 standard equivalent lists—for basic SNR Loss testing

• 3 pairs of standard lists—additional list pairs for research

• 3 practice lists (not equivalent to lists 1-12)—for practice only

• 12 lists with speech on channel 1 and constant-level babble on channel 2 (separated)—to demonstrate directional microphone effectiveness

• 12 lists recorded with 30 dB high frequency emphasis (HFE)—for use with ski-slope losses

• 2 pairs of HFE lists—additional list pairs for research

• 12 lists recorded with 30 dB HFE and low pass filtering (HFE-LP)—for use incombination with the HFE lists to determine whether hearing aids withextended HFE will help or degrade speech intelligibility in noise

• 2 pairs of HFE-LP filtered lists—additional list pairs for research

TRACKS:

Track 1 1-kHz calibration toneTrack 2 IdentificationTracks 3-14 Standard QuickSIN lists 1-12.

These twelve lists are equivalent.Tracks 15-20 List pairs. Lists 13/14, 15/16 and

17/18.Tracks 21-23 Practice lists A, B and C. These

lists are for practice only and are notequivalent to the standard lists or list pairs.

Tracks 24- 35 Lists 1-12 recorded with sentences on channel 1 and constant-levelbabble on channel 2. These lists can be usedto demonstrate directional microphone performance (see page 11).

Tracks 36-47 Lists 1-12 recorded with 30 dBhigh-frequency emphasis (HFE). The HFE isused to make speech sounds audible for persons with ski-slope loss.

Tracks 48-51 Two list pairs with 30 dBHFE. List pairs 13/14 and 15/16.

Tracks 52-63 Lists 1-12 recorded withHFE plus 3-kHz low-pass brickwallfilter; to be used in combination withthe HFE lists to predict the outcome offitting hearing aids with extended HFE(see page 10).

Tracks 64-67 Two list pairs with HFE-LP.List pairs 13/14 and 15/16.

Track 68 Speech spectrum noise recorded at 0 VU re: 1-kHz cal tone.

Track 69 Pink noise recorded at 0 VU re: 1-kHz cal tone.

5

HOW TO USE THIS CD

Every CD has two channels: channel one (left) and channel two (right). The QuickSINCD contains the identical recording on left and right channels on all tracks, except forTracks 24-35, which have the target talker on the left and the 4-talker babble on theright.

Setup:Connect a CD player to the external input of the audiometer. The QuickSIN test maybe presented via loudspeaker, insert earphones or TDH earphones. When presentingthe QuickSIN test via loudspeaker, present it through one loudspeaker only, with thesubject seated facing the loudspeaker (00 azimuth). When using insert earphones orTDH earphones, you may present the test either monaurally or binaurally. Mostnormative data were collected using binaural presentation.

Calibration:Using the 1-kHz calibration tone on Track 1, adjust the audiometer so that the VUmeter reads “0.” Some audiometers have two VU meters, one for each channel.When presenting the test via loudspeaker, it is only necessary to set the VU meter forthe channel being directed to the loudspeaker. When presenting the test viaearphones, it may be necessary with some audiometers to adjust both VU meters.NOTE: Tracks 24-35 were recorded with speech on one channel and babble on theother. When using these tracks, calibrate both channels.

Presentation Level:For pure tone average (PTA) <45 dB HL, set the attenuator dial to 70 dB HL. For PTA of 50 dB HL or greater, set the attenuator dial to a level that is judged to be “loud, but OK.”The sound should be perceived as loud, but not uncomfortably loud. (See Appendix A.)The practice lists on Tracks 21-23 can be used to determine the correct presentationlevel.

Test Instructions:“Imagine that you are at a party. There will be a woman talking and several othertalkers in the background. The woman’s voice is easy to hear at first, because hervoice is louder than the others. Repeat each sentence the woman says. Thebackground talkers will gradually become louder, making it difficult to understand thewoman’s voice, but please guess and repeat as much of each sentence as possible.”NOTE: When testing via loudspeaker, the talkback microphone should be held closeto the patient’s mouth so that responses are clearly audible to the tester.

Pausing:Use the PAUSE button between sentences if the patient responds slowly.

6

PRACTICE LISTS

Tracks 21-23 contain Practice Lists A-C. They can be used to familiarize thepatient with the test protocol or to determine the “loud but OK” presentation level for persons with hearing loss of 50 dB HL and greater. These lists are NOTequivalent to lists 1-12 or list pairs, and do not reliably predict SNR Loss.

TRACK 21Practice List A Score1. The lake sparkled in the red hot sun. S/N 25 ________

2. Tend the sheep while the dog wanders. S/N 20 ________

3. Take two shares as a fair profit. S/N 15 ________

4. North winds bring colds and fevers. S/N 10 ________

5. A sash of gold silk will trim her dress. S/N 5 ________

6. Fake stones shine but cost little. S/N 0 ________

TOTAL ________

TRACK 22Practice List B Score1. Wake and rise, and step into the green outdoors. S/N 25 ________

2. Next Sunday is the twelfth of the month. S/N 20 ________

3. Every word and phrase he speaks is true. S/N 15 ________

4. Help the weak to preserve their strength. S/N 10 ________

5. Get the trust fund to the bank early. S/N 5 ________

6. A six comes up more often than a ten. S/N 0 ________

TOTAL ________

TRACK 23Practice List C Score1. One step more and the board will collapse. S/N 25 ________

2. Take the match and strike it against your shoe. S/N 20 ________

3. The baby puts his right foot in his mouth. S/N 15 ________

4. The pup jerked the leash as he saw a feline shape. S/N 10 ________

5. Leave now and you will arrive on time. S/N 5 ________

6. She saw a cat in the neighbor’s house. S/N 0 ________

TOTAL ________

7

8

WHAT IS SNR LOSS?

We are interested in the patient’s performance in noise compared to normal-hearingpersons’ performance in noise. We consider this difference in performance the SNR Loss.

Similar to the definition of pure tone hearing loss, SNR Loss is defined as the dBincrease in signal-to-noise ratio required by a hearing-impaired person to understandspeech in noise, compared to someone with normal hearing. A normal-hearingperson requires about +2 dB signal-to-noise ratio (speech louder than thebackground noise by 2 dB) to identify 50% of key words in sentences on theQuickSIN test. The value of SNR Loss is derived from the SNR-50 (signal-to-noiseratio for 50% correct) score. A hearing-impaired person who requires speech to be 8 dB higher than the noise to achieve a 50% correct score would have a 6 dB SNRLoss (see Figure 1).

Different tests will give different values of SNR-50 for the same patient. We havefound that changing from a female to male talker and using easier sentencesdecreases the normal SNR-50 by 5 dB from +2 to –3 dB, even though the babblenoise is identical in both tests. Similarly, when continuous speech-spectrum noise isused, the reported SNR will differ by about 7 dB between computed rms calibrationand traditional frequent-peak VU-meter readings (Ludvigsen and Killion, 1997). We’vechosen to report QuickSINscores in SNR Loss because itis substantially independentof calibration and testmaterial. Calibration and/ortest material differences thataffect the SNR-50 valuesequally for normal andhearing-impaired subjects willcancel out in the SNR Losscalculation.

SCORING:

Five key words are scored in each sentence. The key words are underlined on thescore sheets. One point is given for each key word repeated correctly. The number of

Figure 1 (From Killion, 2002)

9

correct words for each sentence should be written in the space provided at the end ofthe sentence and the total correct calculated for the list. SNR Loss is calculated foreach list by using the formula: SNR Loss = 25.5 – Total Correct.

Note: For greater accuracy, two or more lists should be averaged (see pp 19-20).

WHERE DOES THE NUMBER 25.5 COME FROM?

First we need to explain where the number 27.5 comes from. Following the Tillman-Olsen (1973) recommended method for obtaining spondee thresholds, we have asimple method for estimating SNR-50 using nothing more than the total number ofwords correct. In the Tillman-Olsen method, two spondees are presented at eachlevel, starting at a level where all spondees are repeated correctly and decreasing intwo dB steps until no responses are obtained for several words. The starting level plus1 dB, minus the total number of spondees repeated correctly, is the spondeethreshold. The simple arithmetic comes from the use of 2 dB steps and 2 words perstep. If the audiometer only has 5 dB steps, the corresponding method would use 5words per step and take the starting level plus 2.5 dB (half of the step size, just as inthe case of 2 dB steps), minus the total number of spondees repeated correctly.

The QuickSIN has five words per step and 5 dB per step. Our highest SNR is 25 dB so we take 25 + 2.5 = 27.5 minus the total number of words repeated correctly. This gives what we call SNR-50, the signal-to-noise ratio required for thepatient to repeat 50% of the words correctly. For example, if someone repeats all thewords correctly down to 15 dB SNR and then misses everything beyond that point,they gave 15 correct responses (five each at 25, 20, and 15 dB SNR). Since theyscored 100% correct at 15 dB SNR and 0% correct at 10 dB SNR, their SNR-50would be about 12.5 dB, halfway between 15 and 10. This is the value given by theformula 27.5-15 = 12.5 dB.

THE FORMULA FOR SNR LOSS:

Since SNR-50 for normal-hearing persons is 2 dB, we subtract 2 dB to derive theformula for a patient's SNR LOSS: 25.5 – (Total words correct in 6 sentences)

SNR loss = SNR-50 – 2 dB= 27.5 – (total words correct) – 2 dB= 25.5 – (total words correct)

GUILT-FREE QuickSIN TEST: for ski-slope loss

High-Frequency Lists & Low-Pass-Filtered Lists

Figure 2 shows the high-frequencyemphasis added to the QuickSINlists to obtain the recordingslabeled HFE. This frequencyresponse was obtained from FIG 6(1997) for 65 dB (normal speech)inputs for a patient with 60-70 dB ski-slope loss.

Data on ski-slope hearing loss from Skinner (1980), Rankovic (1991), andTurner and Cummings (1999) indicate that some patients do worse with theextended high frequency emphasis prescribed by popular formulae than if theemphasis is restricted to regions of better hearing. Other patients with similar audiograms seem to benefit from the extended high-frequency amplification.

A new set of recordings labeled HFE-LP were generated by low-pass filtering the HFE recordings with a brickwall filter set at 2.5 kHz. The resulting frequencyresponse is also shown in Figure 2.

By comparing the SNR results obtained with the HFE and HFE-LP lists, it is possibleto determine whether or not extended high-frequency amplification is useful. For atest accurate to 1.9 dB (95% confidence interval for the difference between the twoconditions), four HFE and four HFE-LP lists are required, a total of 8 independentlists used alternately.

Example: Track 36 (list 1 with HFE) and Track 53 (list 2 with HFE-LP)Track 38 (list 3 with HFE) and Track 55 (list 4 with HFE-LP)Track 40 (list 5 with HFE) and Track 57 (list 6 with HFE-LP)Track 42 (list 7 with HFE) and Track 59 (list 8 with HFE-LP)

Note: The same list is never used twice in this example.

10

Figure 2

SEPARATED SPEECH & NOISE CHANNELS

Tracks 24-35 contain the 12 standard QuickSIN lists recorded with the speech andnoise on two separate channels (target speech on channel one and 4-talker babbleon channel two). The purpose of these lists is to provide a quick way to verify theeffectiveness of hearing aids that have switchable directional microphones. On thesetracks, both speech and babble were recorded at constant levels; therefore, thetester must establish and control the signal-to-noise ratios by selecting thepresentation levels for both speech and babble channels, and manually change thelevel of the babble channel for each sentence to adjust the signal-to-noise ratio.

Directional Comparisons

A complete measurement of a directional hearing aid requires extensive laboratoryfacilities, but a good demonstration of the ability of directional hearing aids to rejectsound from the sides and rear can be obtained in a standard test booth withloudspeakers located in the corners (at +45o and -45o or 0o and 180o azimuth).

It is important to remember that any test conducted in a sound booth will notprecisely reflect results in the real world. By design, sound booths have minimalreverberation, and testing is conducting using a limited number of loudspeakers(usually two) that are in fixed locations. In this setup, it is possible that the location of the speakers may interact with the null of the directional microphone(s). Therefore,these measures should not be used to assess effectiveness of one directionalmicrophone design vs. another (where differences are usually small) but rather as ageneral measure comparing OMNI to Directional, to verify that the directionalmicrophones are working and providing directivity (rejection of sound from the sidesand rear).

Procedure:If the loudspeakers are located at +45o and -45o, test each ear separately. Positionthe patient in the sound booth so that speech is presented from in front at 45o andbabble from behind at approximately 135o. Direct the speech (channel one) to theloudspeaker at 45o and direct the babble (channel two) to the loudspeaker at 135o.

Note: There are two possible “45 degree” orientations for the patient. The desiredorientation places the aided ear between the loudspeakers. See Figure 3. When theother ear is tested, the patient will need to be rotated to face the opposite wall andthe speech and babble switched to the opposite speakers.

11

Directional Comparisons Continued

12

Figure 3

Figure 4

If the loudspeakers are located at 0o and 180o, you may test each ear separately orboth ears together. Position the patient in the sound booth so that speech ispresented from in front at 0o and babble from behind at 180o

. See Figure 4.

Since the babble noise on Tracks 24-35 is at a constant level, two types ofdemonstrations are possible:1. Subjective. Calibrate both channels. Have the patient set the hearing aid/s to

OMNI. Adjust the speech to 50 dB HL (65 dB SPL conversational speech level)and then adjust the noise to the level where the patient reports that it justprevents understanding the speech. Have the patient switch back and forthbetween OMNI and Directional positions on the hearing aid/s. The improvedintelligibility in the directional mode should be obvious.

2. Objective. Calibrate both channels. Set the dial for channel one (front speaker)to 50 dB HL. Set the dial for channel two to 25 dB HL for the first sentence, andincrease the dial setting for channel two (babble) by 5 dB for each succeedingsentence (see Table 2). Score each list as before to obtain SNR Loss. Test inOMNI and Directional. A minimum of three lists in each condition (six total) isrequired for a valid comparison to an accuracy of 1.5 dB at the 80% confidencelevel (see page 20). If you find a difference greater than 4 dB with one list ineach condition, you have already reached the 95% confidence level.

13

Table 2

Channel 1 Channel 2 Dial (dB HL) Dial (dB HL) SNR (dB)

Sentence 1 50 25 25Sentence 2 50 30 20Sentence 3 50 35 15Sentence 4 50 40 10Sentence 5 50 45 5Sentence 6 50 50 0

TEST DEVELOPMENT

The Original SIN TestThe original Etymotic Research Speech-In-Noise (SIN) Test was designed toassess word recognition performance in noise, with and without hearing aids.Test results are reported as signal-to-noise ratio (SNR) for 50% correct. This isconsistent with normal audiometric practice, where threshold is defined as thelevel at which the patient responds 50% of the time. The recommendedpresentation levels for the SIN Test (70 dB HL and 40 dB HL) were selected torepresent the range of typically loud and quiet speech levels encountered by mostpeople in everyday life.

SIN Test Format Sentence materials were used in the SIN Test because sentences spoken withnatural dynamics have greater dynamic range than monosyllabic words, and arethus a more valid representation of real speech (Villchur, 1982). In the real world,the speech dynamic range is increased by the stress given to some words andsyllables vs. the drop in level given to others. The effects of co-articulation are notwell represented on monosyllabic word lists. Monosyllabic words, recorded andplayed back at specific intensity levels, are not representative of speech in thereal world.

One drawback of using sentence materials, however, is that tests which usesentence formats sometimes present an entire sentence to obtain one scorableitem (i.e. one word or the entire sentence is scored as correct or incorrect). Theresult is that significantly greater test time is needed for a given reliabilitycompared to word scoring. The SIN and QuickSIN tests are “words in sentences”tasks, in which 5 words are scored in each sentence, providing a larger amount ofscorable material in a given amount of time. The sentence materials used in theSIN and QuickSIN tests (IEEE sentences) use words that are typically not highlypredictable from the surrounding context, resulting in a performance-intensityfunction that is not unlike that obtained with NU-6 monosyllables (Rabinowitz et.al., 1992). Indeed, an analysis of the relative independence of these wordsindicated that 25 words in five sentences, using half-word scoring, give theequivalent of 27 independent words with whole-word scoring.

Origin of SIN Test Sentence MaterialsThe IEEE (Institute of Electrical and Electronics Engineers) sentences were derivedfrom the Harvard Phonetically Balanced Sentences, developed at Harvard Universityduring World War II (Braida, 2000). The IEEE formed a subcommittee that wascharged with developing practice guidelines for speech quality measurements tohelp communication engineers assess speech transmission systems. The 720 IEEE

14

sentences (72 lists of 10 sentences each, with five key words in each sentence) werepublished as Appendix C in the 1969 document, “IEEE Recommended Practice forSpeech Quality Measurements.” According to Silbiger (2000), the sentences used inthe IEEE document were originally published in 1944 (Egan, 1944). The IEEEsentences were designed to have few contextual cues to aid in understanding, i.e. if a listener hears the first part of the sentence, s/he cannot likely “fill in” the remainderbased on contextual cues and knowledge of the language.

As part of her doctoral dissertation, Fikret-Pasa (1993) obtained recordings of theIEEE sentences (female talker) from the Massachusetts Institute of Technology onDAT, and equalized them to correct for the high-frequency attenuation caused by thechest position of the recording microphone used at MIT. This recording was used ingenerating sentences for both the SIN and the QuickSIN tests.

Problems with the SIN Test:Many practitioners reported that administration of the SIN Test was too time-consuming for clinical use, and scoring the test was difficult and cumbersome.After several in-depth analyses of the SIN Test, it was discovered that several of thelists were not equivalent, resulting in too few lists available for some clinicalcomparisons and research purposes (Bentler 2000). Some subjects could not attaina 50% correct score, even at the best (+15 dB) signal-to-noise ratio.

Background NoiseThe choice of background noise is an important component of any test. Thepurpose of the SIN test was to obtain an estimate of difficulty hearing in noise thatis representative of real-world performance. Sperry, Wiley & Chial (1997) found thata meaningful speech competitor had a significantly more adverse effect on wordrecognition performance compared to non-meaningful competitors (e.g. shapednoise or backward multitalker). While the spectrum and masking effects of speech-shaped noise are much easier to control, speech-shaped noise is notrepresentative of the type of noise encountered by normal-hearing persons in theireveryday environments.

The SIN and QuickSIN tests use a four-talker babble recording (Auditec of St. Louis)with one male and three females. The four-talker babble represents a realisticsimulation of a social gathering, in which the listener may “tune out” the targettalker and “tune in” one or more of the background talkers. It provides a goodrepresentation of the difficulty that patients face—the situation in which what theywant to hear is speech, and what they don’t want to hear is also speech. During theQuickSIN test development, research subjects frequently commented, “This is what it sounds like to me; this is what it sounds like to have a hearing loss and tryto listen in a noisy place!”

15

16

QuickSIN Search for Sentence Equivalence

Alpha VersionsThe original SIN Test used the first 360 sentences (lists 1-36) of the 720 IEEEsentences. The QuickSIN sentences were selected from among the remaining360 sentences (lists 37-72) and were re-recorded, along with the four-talkerbabble, on separate tracks of an eight-track digital recorder. Thus, all subsequentre-recordings of a given sentence had the same time-locked sequence of babble.This was important because the conversational ebb and flow of the naturalconversational speech produced by the four babble talkers meant that the overallnoise level varied from moment to moment. Moreover, not all of the IEEEsentences are equivalent in terms of difficulty.

In order to determine the SNR-50 of each sentence in its accompanying babblesegment, IEEE sentence lists 37-72 were recorded on the “Alpha-1 version” set ofthree CDs at nominal signal-to-noise-ratios of -1, +2, and +5 dB. The sentenceswere presented to sixteen normal-hearing subjects at 70 dB HL via ER-3A insertearphones. The three signal-to-noise ratios (-1, +2, and +5 dB) were presented inthat order. An across-subject average SNR-50 was obtained for each sentence.This value was used to adjust the SNR on a sentence-by-sentence basis to anexpected value of 2 dB, the grand average value. The resulting set of recordingsbecame the Alpha-2 set of CDs.

At this point, the sentences were subjected to a taste test committee that requiredthe sentences to be grammatically acceptable and contemporary (as opposed tothe 1940s when the IEEE sentences were created). Sentences surviving the tastetest were subjected to the following statistical criteria for SNR equivalence:

1. The standard deviation of the SNR-50 values across six normal-hearing adultsubjects was less than 1.5 dB on the Alpha-2 recordings;

2. The mean SNR-50 value on six normal-hearing adult subjects was within 1.5 dB of their grand average on the Alpha-2 recordings;

3. The mean SNR-50 value on eight high-frequency-loss adult subjects waswithin 2 dB of their grand average on the Alpha-2 recordings;

4. The range of individual-word SNR-50 values within a given sentenceexceeded 2 dB (data from six randomly-selected subjects from the 16 normal-hearing adult subject pool on the Alpha-1 recordings).

Beta VersionStarting with the original 360 sentences, the procedure just described eliminatedall but 89 sentences, giving enough sentences for 14 lists of six sentences, oneeach at 25, 20, 15, 10, 5, and 0 dB SNR. Lists 1-14 on the Beta version usedthese 14 lists. Since we wanted at least 20 lists, we obtained another seven listsby opening up the standard deviation in #2 from 1.5 to 2.0 dB. Lists 15-21 on theBeta version of the QuickSIN test used the more lax criteria.

Beta Site ProtocolCD recordings of the beta version QuickSIN lists (21 lists of six sentences each)were sent to approximately two dozen sites. The test protocol controlled for orderand learning effects. Test/retest data were required for all 21 lists for both normaland hearing-impaired subjects.

Normal subjectsBeta version QuickSIN tests were analyzed for 26 normal-hearing listeners (14subjects from eleven sites, and 12 subjects from a University of Iowa clinic) and18 hearing-impaired subjects from ten sites. Some data were excluded fromanalysis if the test protocol was not followed correctly. Analysis of listpresentation order indicated that adequate counter-balancing for list order wasachieved. The across-subject average across lists for normal-hearing subjects wasSNR-50 = 1.9 dB, nearly identical to the original SIN Test average of 2 dB.

Hearing-Impaired (simulated):Normal-subject results alone are not adequate to determine list equivalence, sinceperformance for normal-hearing listeners is typically determined primarily by thesentences recorded at 0 and 5 dB SNR. In order to check list equivalence forhigher SNR levels, we simulated varying degrees of high-frequency hearing lossusing filtering.

The 21 Beta-test lists were re-recorded using low-pass brickwall filter settings of750 Hz, 850 Hz, 1100 Hz, 1400 Hz, and 2000 Hz. Each recording was presentedto 25 normal-hearing subjects. Subjects were tested in three sessions overseveral days, and list number presentation order was varied to counterbalance forpotential order effects. The most difficult condition (750 Hz low pass) waspresented first, followed in order by the less difficult conditions. Testing wascompleted over several days, thus “learning effects” were not expected despiterepeated presentations of the same lists.

17

18

Figure 5 shows a plot of across-subject QuickSIN Beta averages for 25 normal-hearingadult subjects at each filtering condition. The twelve lists without an X exhibited SNR-50 values at each filtering condition that fell within ± 2.2 dB of the grand average.In addition, three pairs of lists were found whose pair average met those criteria.(Typically one list score would be high and the other would be low under similarconditions.) By adding those paired lists, a total of 15 equivalent lists becameavailable (12 lists plus 3 list pairs).

Figure 6 shows a plot of the across- subject average data (renumbered lists) for thelists included on the final QuickSIN CD.

Figure 6

Figure 5

RELIABILITY (STATISTICS MADE USEFUL)

A QuickSIN score obtained in one minute from a single list is accurate to about1.8 dB at the 80% confidence level. By “about” we mean that 80% of the time(four times out of five) the “true” score (obtained from many lists) will be within1.8 dB of the single-list test score. Statisticians would say we have “an 80%confidence level” that the true QuickSIN score will be within + 1.8 dB of themeasured score. To put these numbers in perspective, a typical clinical thresholdis accurate to about 5 dB at the 80% confidence level. In other words, one timeout of five a threshold can be expected to be 5 dB or more above or below therecorded value. An 80% confidence level is normally adequate for clinical testing,where the results of any one test are used in context with other factors. In thecase of a test of SNR Loss, for example, the clinician will already have formed anidea of the patient’s communication difficulty from conversations with the patient.A 95% confidence level is common for research reporting, where a reduced risk oferror is normally required. Using a statistical criterion that gives a 95% confidencelevel reduces the probability of error to one time in twenty.

Table 3 below shows the number of lists required for a given accuracy forconfidence levels of 80%, 90% and 95%.

Table 3

The numbers in Table 3 are based on the rms average standard deviation of 1.4 dB in SNR found for the hearing-impaired subjects included in the Beta-sitetesting. This figure comes from two numbers: a) the 1.3 standard deviationderived from the combined individual test-retest scores, and b) the across-liststandard deviation of 0.6 dB. If only normal-hearing subjects are used, theappropriate standard deviation drops from 1.4 dB to 1.25 dB. A standarddeviation of 1.4 dB is slightly better than the standard deviation which would havebeen expected based on the original SIN Test. That standard deviation of 0.7 dB,multiplied by the square root of five, would predict a standard deviation of 1.6 dB for the QuickSIN test which uses only one sentence at each levelcompared to five sentences at each level on the SIN Test. The more carefulpreselection of sentences used in the QuickSIN test may have contributed tothe slightly better result.

19

Number of Lists 1 2 3 4 5 6 7 8 9

95% C.I. ±, in dB 2.7 1.9 1.6 1.4 1.2 1.1 1.0 1.0 0.990% C.I. ±, in dB 2.2 1.6 1.3 1.1 1.0 0.9 0.8 0.8 0.780% C.I. ±, in dB 1.8 1.3 1.0 0.9 0.8 0.7 0.7 0.6 0.6

20

COMPARISON BETWEEN TWOCONDITIONS

Averaging the results of several QuickSIN lists improves the reliability compared toa single list. This is particularly important when QuickSIN lists are used to comparetwo conditions, often two hearing aids or hearing aid adjustments. In this case, thereal differences may not be large.

Table 4 below gives the number of lists required for the comparison between two conditions at an 80%, 90% or 95% confidence level. For a critical differenceof 1.9 dB, for example, four lists are required for each condition at the 95% level.For a critical difference of 1.4 dB at the 95% confidence level, eight lists arerequired for each condition. For a simple example, one list in each condition withthe assumed standard deviation of 1.4 dB gives a 95% confidence level of 1.96 x 1.41 x 1.4 = 3.9 dB.

To improve from 80% to 95% confidence level at a given criterion requires anapproximate doubling of test time. Example: Two lists in each condition gives a 1.8 dB critical difference at the 80% confidence level; four lists in each conditionprovide 1.9 dB at the 95% confidence level, and five lists in each conditionprovide 1.7 dB at the 95% confidence level.

Table 4

When comparing HFE and HFE-LP conditions for a patient with ski-slope loss, onemight well accept an 80% confidence level (one in five chance of being wrong), andconsider anything less than 1.5 dB as not practically significant. In this case, Table 4indicates that three lists in each condition would suffice. This will typically take sixminutes, which is relatively small compared to the time often taken fightingfeedback. (A relaxed criterion of 1.8 dB would require only two lists in eachcondition, or four minutes of testing). If the test results indicate that high-frequencyemphasis which ends at about 2.5 kHz gives as good or better scores, the cliniciancan abandon the feedback fight without guilt.

Lists per Condition 1 2 3 4 5 6 7 8 9

95% C.D. ±, in dB 3.9 2.7 2.2 1.9 1.7 1.6 1.5 1.4 1.390% C.D. ±, in dB 3.2 2.2 1.8 1.6 1.4 1.3 1.2 1.1 1.180% C.D. ±, in dB 2.5 1.8 1.5 1.3 1.1 1.0 1.0 0.9 0.8

APPENDIX A

CATEGORIES OF LOUDNESS

7. Uncomfortably Loud

6. Loud, But OK

5. Comfortable, But Slightly Loud

4. Comfortable

3. Comfortable, But Slightly Soft

2. Soft

1. Very Soft

Valente and Van Vliet (1997)

24

25

APPENDIX BTECHNICAL NOTE: CROSSTALK

On Tracks 24-35, the target speech and the babble are recorded on separatechannels, but a small amount of interchannel crosstalk (-65 dB) exists on theQuickSIN CD. The typical CD player with a 1/8th-inch stereo plug can increase the crosstalk another 20-30 dB, and most cassette players have even greatercrosstalk between their magnetic playback heads. Under normal conditions noneof these levels will be audible, but during silent periods on the sentence channel,a faint babble can sometimes be heard in the background. None of these crosstalklevels will affect normal usage of these tracks.

26

REFERENCES

Bentler, R (2000). List Equivalency and Test-Retest Reliability of the Speech in Noise Test. Am J Audiol, 9 (2): 84-100.

Braida, L (2000). Personal communication.

Egan, JP (1944). Articulation Testing Methods II. Office of Research and Development, Report 3802. PB 22848.

Etymotic Research (1993). The SIN Test (Compact Disk) 61 Martin Lane, Elk Grove Village, Illinois 60007.

Etymotic Research (1997). FIG 6 for Windows (3.5" diskette) 61 Martin Lane, Elk Grove Village, Illinois 60007.

Fikret-Pasa, S (1993). The Effects of Compression Ratio on Speech Intelligibility and Quality. Northwestern UniversityPh.D. Dissertation, University Microfilms, Ann Arbor, MI.

Killion, M (1985). The Noise Problem: There’s Hope. Hearing Instruments, 36 (11): 26-32.

Killion, M (2002). New Thinking on Hearing in Noise: A Generalized Articulation Index. Seminars in Hearing, 23 (1): 57-75.

Killion, M, Niquette, P (2000). What Can the Pure-Tone Audiogram Tell Us About A Patient’s SNR Loss? The HearingJournal, 53 (3): 46-53.

Killion, MC, Niquette, PA, Gudmundsen, GI, Revit, LJ, and Banerjee, S (2004). Development of a quick speech-in-noisetest for measuring signal-to-noise ratio loss in normal-hearing and hearing-impaired listeners. J Acoust Soc Am116(4): 2395-2405.

Killion, MC, Niquette, PA, Gudmundsen, GI, Revit, LJ, and Banerjee, S (2006). Erratum: Development of a quick speech-in-noise test for measuring signal-to-noise ratio loss in normal-hearing and hearing-impaired listeners.J Acoust Soc Am 119(3).

Ludvigsen, C, Killion, M (1997). Personal communication

Martin, FN, Champlin, CA, Perez, DD (2000). The Question of Phonetic Balance in Word Recognition Testing.J Am Acad Audiol, 11 (9): 489-493.

Rabinowitz, W, Eddington, D, Delhorne, L, Cuneo, P (1992). Relations Among Different Measures of Speech Reception in Subjects Using a Cochlear Implant. J Am Acoust Soc, 92:1869-1881.

Rankovic, CM (1991). An Application of the Articulation Index to Hearing Aid Fitting J SP Hear Res, 34:391-402.

Silbiger, H (2000). Personal communication.

Skinner, MW (1980). Speech Intelligibility in Noise-Induced Hearing Loss: Effects of High-Frequency Compensation.J Am Acoust Soc, 67:306-317.

Sperry, JL, Wiley, TL, Chial, M.R (1997). Word Recognition Performance in Various Background Competitors.J Am Acad Audiol, 8 (2): 71-80.

Stockley, KB, Green, WB (2000). Interlist Equivalency of the Northwestern University Auditory Test No. 6 in Quiet andNoise with Adult Hearing-Impaired Individuals. J Am Acad Audiol, 11 (2): 91-96.

Tillman, TW, Olsen, WO (1973). Speech Audiometry. In: Modern Developments in Audiology. Second Edition.Jerger, J (ed). Academic Press, New York.

Turner CW, Cummings, KJ (1999). Speech Audibility for Listeners With High-Frequency Hearing Loss.Am J Audiol, 8 (1):47-56.

Valente, M, Van Vliet, D (1997). The Independent Hearing Aid Fitting Forum (IHAFF) Protocol. Trends in Amplification,2 (1): 6-35.

Villchur, E (1982). The Evaluation of Amplitude-Compression Processing for Hearing Aids. In: The Vanderbilt Hearing AidReport. Studebaker, G. & Bess, F. (eds). Monographs in Contemporary Audiology, Upper Darby, PA.

27

Track 1 Calibration Tone

Track 2 Identification

Tracks 3-14 QuickSIN Lists 1-12

Tracks 15-20 QuickSIN List Pairs 13/14, 15/16, 17/18

Tracks 21-23 Practice Lists A, B, C

Tracks 24-35 Separated Speech and Babble

Tracks 36-47 HFE: Lists 1-12 (30 dB high-frequency emphasis)

Tracks 48-51 HFE List Pairs 13/14, 15/16

Tracks 52-63 HFE-LP Lists 1-12 (HFE plus 3 kHz low-pass)

Tracks 64-67 HFE-LP List Pairs 13/14, 15/16

Track 68 Speech Spectrum Noise Recorded at 0 VU re: cal tone on Track 1

Track 69 Pink Noise Recorded at 0 VU re: cal tone on Track 1

ETYMOTIC RESEARCH, INC.61 Martin LaneElk Grove Village, IL 60007www.etymotic.com

Re-recording: Larry Revit / Revitronix

©2001 ©2006 ER029002A 0206 Designed

QuickSIN ™

Speech-in-Noise Test